i mean, i have 1 video clip showing a tree. and then i have 1 .jpg image of an airplane

how can i make that airplane from jpg image to appear in the video showing the tree? i want to make that airplane crash into the tree and explode.

i see a lot of similar stuff on youtube (like "cyriak animation mix") but i don't know what this technique is called. animation of still images? google search gave me lots of dubious results, none of them came straight to the point.

all i know it involves some manipulation of keyframes but i need to know more keywords to further research this technique. or better yet - find a decent article explaining basics.

First, you will probably want to Key out the background around the plane. Look into Chorma Key, or one of the other Keying Effects in PrE, depending on how the plane was shot, or created. If you created it, you can probably Mask out any background, and Save_As a format, that support Transparency, such as with an Alpha Channel Mask.

Actaully, it's called the Pan & Zoom tool, and it's used for creating motion paths -- so it may not be exactly what you're looking for. But it's launched by clicking the blue button along the tip left of the Timeline.

You can find out more about it by clicking on the tutorial on the lower left of this page.